On the Trinity (my least favorite doctrine)

From a young age my dad shared his concerns about this formulation that seemed to be illogical. I understood and absorbed his hesitation and my doubts grew as I wrestled through youth group and into Bible College. The doctrine of the Trinity just never made sense to me but it seems like nearly every other orthodox Christian throughout history believed it, so I kept trying.  What made it possible for other people to so easily accept Trinity as basic fact?  What did they know that I didn't?  Or did they just not care?